On Fri, 23 Jul 2021 at 18:22, Jason Ekstrand jason@jlekstrand.net wrote:
__i915_ttm_get_pages does two things. First, it calls ttm_bo_validate() to check the given placement and migrate the BO if needed. Then, it updates the GEM object to match, in case the object was migrated. If no migration occured, however, we might still have pages on the GEM object in which case we don't need to fetch them from TTM and call __i915_gem_object_set_pages. This hasn't been a problem before because the primary user of __i915_ttm_get_pages is __i915_gem_object_get_pages which only calls it if the GEM object doesn't have pages.
However, i915_ttm_migrate also uses __i915_ttm_get_pages to do the migration so this meant it was unsafe to call on an already populated object. This patch checks i915_gem_object_has_pages() before trying to __i915_gem_object_set_pages so i915_ttm_migrate is safe to call, even on populated objects.
Signed-off-by: Jason Ekstrand jason@jlekstrand.net
Reviewed-by: Matthew Auld matthew.auld@intel.com